Automatic chisel hammer



Aug. 30, 1927. 1,641,031

.M. W. GAiLLARD AUTOMATIC CHISEL HAMMER Filed Aug. 6, 1926 muwl u a m g iling A gm 7 24- 29 avg? Patented Aug. 30, 1927.

' UNITEDQSTATES PATENT OEFECE.

MADISON WILSON eArLLAnn, or MOBILE, AIJABAMA.

AUTOMATIC cnrsnn HAMMER.

Application filed August 6, 1926. Serial No. 12 7,711,

The present invention relates to improvements in automatic ch1selhammer and has for-an ob ect to provide an improved instrument fordental and other uses in whicha reciprocating hammer action is produced for the purpose of chipping away enamel, plugging teeth, chipping rust from ships, etc.

fAnother object of the invention lies in providing an improved tool of the character above described in which the hammer action is direct and automatic and in which the parts aresimple, few and easily accessible andin whichthe entire instrument is compact, light and easily handled.

ll ith'the foregoing and other objects in view, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claims appended hereto. 7 v r In the drawings, wherein like symbols refer to like or corresponding parts throughout the several views,

Figure 1 is a plan view of an improved instrument constructed according to the present invention. 7 v

Figure 2 is a side view thereof. 7

Figure 3 is a section taken on an enlarged scale along the line 3-3 in'Figure l with a portion of the handle broken away.

Figure 4: is a vertical section taken on the line 4- 4 in Figure 3, and

Figure 5 is a horizontal section taken on the line 5-5 in Figure 3.

Referringmore particularly to the drawings 6 designates the handle of the tool which may conform to anyshape desired and through which passes the rotary shaft 7 adapted to have connection with a dental engine or other source of power by which the shaft may be continuously rotated.

The end of the shaft projects beyond the end of the handle 6 where it carries the cam 8 affixed thereto. This cainis adapted to occupy a recess 9 made through the side wall of a weighted plunger or hammer 10 having the cylindrical or other desired form and fitted to reciprocate in the cylindrical or other casing 11, the axis'of which preferably extends at substantially right angles to the axis of the handle and-shaft 7. The

cam 8 is intended to cooperate with theupper wall of the recess 9, which is of come plementary cam form having the inclined wall 12 extending from one edge downwardly toward the central part of the recess,

and resulting in the high cam point 18 adja- At the lower cent which is the abruptshoulder 14C joining the high cam point withthe upwardly offset curved wall15. e

The casing 11 is'provided with the lateral nipple or branch 16' internally threaded as indicated at 17 to screw upon the externally threaded reduced part of the handle 6. The

handle isprovided with a shoulder 18 adjoining the threaded reduced part against which the nipple 16 is adapted to abut. The casing 11 is threaded externally at its upper end, as indicated at 19 to receive the internally threaded and flanged cap 20, which houses and adjusts the coil spring 21 fitted in the upper end of the casing and within the socket 22, which opens downwardly through the top portion of the hammer plunger 10.

threads 23 are provided to receive the internally threaded flange of the lower cap 24, which is provided with a central opening about which extends the depending flange 25 to receive and act as a guide for the stem 3 26 of the tool holder, which is composed of said stem and a headpiece 27 of greater diameter than the stem whereby the tool holder may be prevented from disengagement from the lower cap 24. i

As shown in Figures 3 and cap piece 27 is provided with peripheral notches 28 and a pin 29 is adapted to occupy a selected notch, this pin being driven through an opening made in the lower cap 2%.

The stem 26 ofthe tool holder is provided with the threaded socket to receive the threaded shank 30 of the chisel, hammer or other tool 31. 1

In the operation of the invention, the

shaft is continuously rotated by hand,

vdental engine, or other appropriate source of power. The rotating cam 8 wiping down the inclined wall 12 will raise the hammer plunger 10 when the high point of the cam 8 is beneath the high point 13 of the cam wall. The spring 21 will be compressed, so that when the high point of the cam 8 moves past the high point of the cam 13 and opposite the abruptshoulder 14:, the plunger is released and will descend by gravity and forcibly by the action of the previously compressed coil spring 21. The lower end of the hammer or plunger is designed to strike understood that by pressing the tool 81 end of the casing screw 5 the head or IjU sli

against the tooth or other object, the tool holder has been shifted inwardly ot the easinnto the desired extent, whereby, on descent of the plunger, the head piece 27' will be struck urging the tool against the tooth for the desired purpose.

In the drawings l have shown for convenience of illustration a chisel and this chisel and the plunger are normally held against rotary movement but by removing: the pin 29 the chisel may be turned. The chisel .i:--r beveled and in one position it may cut, any, on the right side of the cavity. By adjuste ing it a (piarter turn such as in pcrmistaible by the arrangement of the notches it and pin 53%), it; may cut baclc ol" the tooth. in other quarter turn o'l the tool holder and the chisel may cut upon the lett side of the cavity and by giving it a further quarter turn the same will out only in front of the cavity. In other words. one chisel can be used in cutting any portion of the tooth. obviating the retpiircnient :tor frequently changing instruments.

The adjustment referred to 'an he made quickly and expeditiously by simply till :screwiin the lower flange cap 21-. 'ihia also givee access to the bottom of the casing; and to the bottom oil the hannner. "l e upper cap Qt] permits of the adjustment of the tension upon the coil spring; E21. no that the force ol' the blow ran be governed nicely. This removable upper cap 20 also given acceas to the upper end oi? the pluini ef and using. The lateral nipple 16 may be readily unscrewed from the handle (5 than oeparao inn both handle and asing; and the casino: forms a. unitary conatruetion iarrving all of the parts with the exception of the cam and it enables the cam and the other pares to be rea (lily sepin'ated.

The device will eliminate heat from trio tion. on the tooth, most; pain. to the patient, and the buzzing noise so disagreeable to the patient. The device will also nave the dentist time. It is: noted that the cam little at the center of the long axis of the hammer and the lifting action is; therefore a direct: one. The device may be also need for heavy mechanical work, such as chip ping" ruot from ships. etc.

It obvious that various changes and. modifications may be made in the details of construction and design of the above specith rally described. embodiment of this invention without (jlepa-rting from the spirit thereof, each changes and modifications being re etrictcd only by the scope oit the following cl a i ms 1 What claimed is:-

1. An instrinncnt as described comprising a handle, a rotary shaitt therein, a, cam on the end oi? the ehat't, a caning; removahly connected with the handle, a. hammer in the 'aeing' having a lateral recess for receiving the am, said recess havirn; an upper cam wall tor UU()l)Ql'&l'll1,fI with said rotary Eam, a coil spring lor urging the plunger in one direction, a removable c: p tor the casing: for adjusting the tension of said coil spring, a removable cap on the other end of eaid ennu having: a nuide Hang and a. tool iolder having a shank .lltllllyfi through said .quide flange and provided with a peripherliy notched enlarged head piece in said t. nicntioinitl cap for cm 'agcment by said annner, and meano carried by said. last menlimied c: p for e K ring the notches; in said head piece i'or adjusting the. tool holder about its axis.

tool an described com irieing a. handle, a shalt mounted for rotation in the handle, a cam on the inner end of the ohai't beyond the handle, a casing removably connected to the inner end of the handle and into which eaid am projects, a hammer in the *aeii'lg oil. piston torn] mounted for longitudinal movement in the raising' in a. direction at right angles to the handle and shalt, said lnnnmer havinp; intermediate its ends a lateral opening to receive said cam and having: the inner wall of the opening constructed to provide a cam ehoulder against which said cam is; adapted to oper: to and oaid can] having an abrupt HilUllltlUl for releasing the cam shoulder of the hammer, a saprinc in the casino; engaging; the inner end of the haminer, a tool. holder carried atthe outer end ol. the nsinc; to receive impact from said hammer and adapted to carry a. tool. and adjustable means mounted on the inner end of the casing for cloning; the name and maiin taining: the hammer in position, eaid adjusting' means adapted to engage the spring and *arv the tenoion oi? the same against said hannner to regulate the to cc of? impact of the hammer against the tool holder.

MADISON "ILSON lAILLARD. 

